用简便方法计算 第一题:0.25×(4+0.8) 第二题:0.26×15.4-2.6×0.54

问题描述:

用简便方法计算 第一题:0.25×(4+0.8) 第二题:0.26×15.4-2.6×0.54

0.25×(4+0.8)
=0.25×4+0.25×0.8
=1+0.2
=1.2
0.26×15.4-2.6×0.54
=2.6×1.54-2.6×0.54
=2.6×(1.54-0.54)
=2.6×1
=2.6